Hi, I was wondering if any of you knew the compression ratio on the 2000 trans am LS-1. I intend to turbocharge it and need to know how much lower it needs to be.

Hi, I was wondering if any of you knew the compression ratio on the 2000 trans am LS-1. I intend to turbocharge it and need to know how much lower it needs to be.

Displacement 5.7L (5665cc, 346ci)

Gross Horsepower 310 @ 5200 RPM, 320 @ 5800 RPM

Bore/Stroke 3.90/3.62

Gross Torque 340 @ 4000 RPM, 330 @ 4400 RPM

Compression Ratio 10.1:1

Maximum RPM 6200

Firing Order 1-8-7-2-6-5-4-3

Out of crate weight= Approximately 390 lbs.

Spark Plug ACDelco 12 ACDelco 41-985

Spark Plug Gap .060”, 1.524 mm


Ls1's compression don't need to be lowered till around the 500rwhp mark. the stock hypereuretic pistons will give up before compression becomes a concern. hope this helps

Thanks alot, that's exactly what I was looking for.

Can anyone help me with a 1974 door rattle problem?

not in a post for a 2000 trans am we can't. There's a certain amount of etiquette we expect on any forums, posting in someone elses topic about something completely different just because you think it might get seen is on of those things you just don't do. now back on topic.

another question, are the stock gears 3.73's and would it be worth it to upgrade to 4.10's. I'm building my car to run a pair of Garret T3's

it depends.

If it's an auto, its either a 3.23, or a 2.73. that can easily be found out.

If it's a manual, all manual cars come stock with 3.42's.......

If you are planning on running garret T3s, it would be the wrong way to go to go up in gear. You need to take gear out of the car, and let the boost take care of the rest. most boost guys really like the 3.23. If you are planning on putting some serious power, and actually wanna put it to the ground, you got some work ahead of you suspension wise. Most importantely, you are gonna need a 12 bolt or a 9"

I personally went w/ a 9", but my car is a manual, and demands a little stronger rear end than even the 12 bolt can offer.


Best of luck with it man!!

It's a manual, I don't drive automatics. I always try to hit the clutch in em. I'm looking at putting a carbon fiber driveshaft in it too. As for suspension I'm going eibach springs and edlebrock braces. So even building for a 1/4 mile car you think 3.23's would be best?

if youre going to be going turbo's, you will w/o a doubt run out of gear in the 1/4 with any more than a 3.42.

I guess it really depends on what tire you're gonna be running. On motor, my car makes 430/430, and i run a 26x10x15 DO5 Hoosier slick. I trap at 120-123 and i am through the traps at 6900rpm with a 4.22 gear. With nitrous the car would be bouncing off the 7k rev limiter way before that.

With a decent turbo setup, you should be around 500+or- depending on the setup. That means you are gonna need a 27or higher tire to hook it up at all, and i'd stay around the stock gear, but wouldnt think to go and bigger than that.

You ought to look into chromoly driveshaft's. Carbon fiber is for show, chromoly is for go. Go to the ls1technationals when its near you, and see what kind of Driveshafts those dudes area all running=Chomoly

For shocks/springs, do it once and do it right, you need at least HAL QA1 F series, preffereably R series if you're a 1/4 guy. I run the F series and they are awesome. I had eibach's on the car, and the rear started sagging, and allows for no adjustment. The QA1's are adjustable height, and 12way adjustable shocks.

Well I'm leaning towards 1/4mile because it seems to be where most of the trans am knowledge is, but I'd prefer to autocross it.

Not to take ANYTHING away from this site, but if you're interested in road racing/AutoX, you might need to get to know this section, and the site in general. There are some incredibly knowledgeable LSx guys there, and some VERY knowledgable RR guys there in this specific section...

http://ls1tech.com/forums/forumdisplay.php?f=35